Transparent solar panels are nothing new. But it's hard for the panels to make the most of sunrays, the efficiency is low and further engineering and development are necessary.
However, efficiency is increased with a new design by a group of researchers from the University of Michigan. In fact, they hit the record with a 8% efficiency.
The research is published in the Proceedings of the National Academy of Sciences.
Tall buildings, which block the sun from reaching down and leaves the cities, are a great source to turn sun rays into energy.
Raising the bar high
The researchers reached 8.1% efficiency and 43.3% transparency thanks to a carbon-based design instead of commonly used silicon.
“The new material we developed, and the structure of the device we built, had to balance multiple trade-offs to provide good sunlight absorption, high voltage, high current, low resistance and color-neutral transparency all at the same time,” explained assistant research scientist Yongxi Li to Michigan News.
There are currently two versions of the solar cells. One is color-neutral, which was made with an indium tin oxide electrode and the efficiency rose up to 10.8% with a 45.8% transparency thanks to a silver electrode. The other one, however, has a slight green tint, which might make it unsuitable for some window applications.
Expecting to reach a large mass
The versions also have an advantage as they are manufactured with less toxic materials, not including silicon.
Organic molecules are engineered to be transparent and absorb near-infrared light, an invisible part of the spectrum that accounts for much of the energy.
Of course, like every ambitious and detailed study, scientists are not done researching. Naturally, are looking to achieve a higher efficiency and are searching for cost-effective ways to install the cells on new and existing buildings.